You're welcome
I've done UNO's Mk I and II, and have a Cinq which looks the same. I guess the Sciento
is the same as the Cinq.
For just the transmission end boot, it's a case of get the front end wheel free,
supported on blocks.
Drain the gearbox oil. Take front wheel off. You then have to decide whether you want
to do just the inner or both boots. If only the inner, you could just take off the hub
and driveshaft as one lump. No need to disturb the big driveshaft nut. Either way,
unbolt the brake caliper and tie it to the strut spring. Undo the 3 ball joints.
Unbolt the hub, a pain in the arse as the bolts are rusted in place. Good idea is to
get Fiat replacement bolts and nuts when you buy the boots, in case you wreck the
originals getting them unrusted, sometimes needs Plusgas, wrench, and a medium hammer
to knock them through. Undo the bolts round the gearbox seal housing. Take off the
hub, driveshaft and seal housing.
Then its just circlips to separate the parts, and re-assemble.
Though you are probably not into DIY, it is not a particularly technical job, just
time and labour, the boots AFAIR about a fiver.
If you undo the driveshaft nut you can take the hub off, then the driveshaft and CV
joint seaparately, it weighs less and is easier to handle.
Over the years I've done most jobs. From the 128's, through the Uno's, and the Cinq.